1. Field of the Invention
The present invention relates to an improved bicycle drive mechanism, whereby energy transmitted through a pedal crank arm to the mechanism is utilized in a more efficient manner, thereby relieving stress upon the bicycle rider.
2. Description of the Related Art
The bicycle has been a tried and proven method of human powered transportation prior to and throughout the present century. Aside from this fact, in terms of efficiency it is renowned as an engineering feat, elegantly demonstrating the true ingenuity of mankind as a species. With this in mind one must consider it no mere coincidence that experts in this field, Wilbur and Orville Wright, were also the progenitors of manned flight.
An early embodiment of the bicycle employed as a drive mechanism a crank operated first sprocket driving a second sprocket by way of a continues loop roller chain, the second sprocket being affixed to the rear wheel of the bicycle. This basic but common design still enjoys widespread use in our present day. An early improvement to this concept of energy transfer was to employ a multiple gear ratio mechanism within the hub of the smaller driven sprocket thereby allowing the rider a choice of up to three different gear ratios. A relatively recent improvement involves employing a first plurality of drive sprockets of various sizes connected by the roller chain to a second plurality of driven sprockets of various sizes. The chain connecting the two separate sets of sprockets is made to move between any combination of the sprockets by a mechanism known as a derailer. In this manner a larger variety of gear ratios are available, ranging from a very low ratio to a relatively high ratio. Other improvements have served to facilitate the ease of operating the above mentioned mechanisms, or producing the bicycle of lighter stronger alloys and comfort enhancing schemes. All of these types of improvements address efficiency somewhat, but to a lesser degree. However, with all of the prior art improvements in the field of bicycle drive mechanisms, which incidentally are in the public domain, none have yet solved the most basic problem, which is utilizing energy transmitted by human muscle tissue in a most advantageous yet simple manner. The improved bicycle drive mechanism disclosed henceforth will overcome this disadvantage and thereby provide a simple solution long sought in the art.